Snapshot 2007-03-20

1 files changed, 59 insertions, 0 deletions

diff --git a/remux/tsremux.c b/remux/tsremux.c
new file mode 100644
index 0000000..6be5245
--- /dev/null
+++ b/remux/tsremux.c
@@ -0,0 +1,59 @@
+#include "remux/tsremux.h"
+
+#define SC_PICTURE 0x00  // "picture header"
+
+void cTSRemux::SetBrokenLink(uchar *Data, int Length)
+{
+  if (Length > 9 && Data[0] == 0 && Data[1] == 0 && Data[2] == 1 && (Data[3] & 0xF0) == VIDEO_STREAM_S) {
+     for (int i = Data[8] + 9; i < Length - 7; i++) { // +9 to skip video packet header
+         if (Data[i] == 0 && Data[i + 1] == 0 && Data[i + 2] == 1 && Data[i + 3] == 0xB8) {
+            if (!(Data[i + 7] & 0x40)) // set flag only if GOP is not closed
+               Data[i + 7] |= 0x20;
+            return;
+            }
+         }
+     dsyslog("SetBrokenLink: no GOP header found in video packet");
+     }
+  else
+     dsyslog("SetBrokenLink: no video packet in frame");
+}
+
+int cTSRemux::GetPid(const uchar *Data)
+{
+  return (((uint16_t)Data[0] & PID_MASK_HI) << 8) | (Data[1] & 0xFF);
+}
+
+int cTSRemux::GetPacketLength(const uchar *Data, int Count, int Offset)
+{
+  // Returns the length of the packet starting at Offset, or -1 if Count is
+  // too small to contain the entire packet.
+  int Length = (Offset + 5 < Count) ? (Data[Offset + 4] << 8) + Data[Offset + 5] + 6 : -1;
+  if (Length > 0 && Offset + Length <= Count)
+     return Length;
+  return -1;
+}
+
+int cTSRemux::ScanVideoPacket(const uchar *Data, int Count, int Offset, uchar &PictureType)
+{
+  // Scans the video packet starting at Offset and returns its length.
+  // If the return value is -1 the packet was not completely in the buffer.
+  int Length = GetPacketLength(Data, Count, Offset);
+  if (Length > 0) {
+     if (Length >= 8) {
+        int i = Offset + 8; // the minimum length of the video packet header
+        i += Data[i] + 1;   // possible additional header bytes
+        for (; i < Offset + Length - 5; i++) {
+            if (Data[i] == 0 && Data[i + 1] == 0 && Data[i + 2] == 1) {
+               switch (Data[i + 3]) {
+                 case SC_PICTURE: PictureType = (Data[i + 5] >> 3) & 0x07;
+                                  return Length;
+                 }
+               }
+            }
+        }
+     PictureType = NO_PICTURE;
+     return Length;
+     }
+  return -1;
+}
+